History 104 Geology 44 Antiquities 29 Law and legislation 27 World War, 1939-1945 26 Public housing 22 Management 21 Planning 21 Finance 19 Safety measures 19 Environmental aspects 18 Local government 18 Sources 18 Guide-books 17 Housing 17 Airports 16 Employment 16 Social conditions 16 Catalogs 15 Economic aspects 15 Exhibitions 15 Regional planning 15 Children 14 Description and travel 14 Hospitals 14 Industries 14 Cities and towns 13 Education 13 Case studies 12 Design and construction 12